package com.example.demo.common;

import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.SneakyThrows;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

@ResponseBody
@ControllerAdvice
public class ResponseAdvice implements ResponseBodyAdvice {
    @Override
    public boolean supports(MethodParameter returnType, Class converterType) {
        return true;
    }

    @SneakyThrows
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        if (body instanceof Result){
            return body;
        }
        // 构造统一返回对象
        Result result = Result.success(body);

        if (body instanceof String) { // 返回类型是 String（特殊）
            ObjectMapper objectMapper = new ObjectMapper();
            return objectMapper.writeValueAsString(result);
        }
        return result;
    }
}
